Peripheral nerves interconnect an individual's central nervous system (CNS) to the other parts of their body, such as limbs, organs and muscles. Unfortunately, peripheral nerve injuries are common, often resulting from trauma or surgical complications. Further, the incidence of peripheral nerve trauma in the military population is increasing and approximately 5 to 10 times greater than in the civilian population. Pathology in this population is caused mainly due to shrapnel from blast events. With the advent of improved core body armor, such as that used in recent military action in the Middle East, the ratio of injuries resulting in wounds rather than death has doubled. This translates into a much higher rate of peripheral trauma, peripheral nerve injury, and amputations.
It can be appreciated that peripheral nerve injuries impose a number of adverse health conditions or disabilities on their victims. These adverse health conditions and disabilities place significant physical and economic burdens on the victims. In addition, these burdens are often shared by the victim's family, community and workplace. Further, adverse health conditions and disabilities resulting from peripheral nerve injuries place significant economic burdens on the health care system and on the economy in general. Considerable amounts of money, time and effort have been expended on various attempts to lessen, prevent or ameliorate the effects of trauma on peripheral nerves.
Despite significant advancements in composite tissue allotransplantion, allowing for upper extremity transplant below the elbow, problems remain with long-term allograft stability secondary to rejection, as well as, with nerve regeneration over long distances. Specific to lower extremity amputation, minimal progress has been made in composite tissue allotransplantation. Thus, the use of prosthetic limbs remains the gold standard for replacing amputated extremities.
In the past several decades, remarkable advancements have been made in the engineering of prosthetic limbs. These improvements include the development of implantable myoelectric interfaces that harness electromyographic data to control prostheses. The regenerative peripheral nerve interface (RPNI) is one such interface that is comprised of a free muscle unit neurotized with a peripheral nerve of interest. Other groups have developed recording interfaces by redirecting nerves from amputated stumps to reinnervate healthy adjacent muscles (Targeted Muscle Reinnervation). In these strategies, the neural interface is primarily composed of soft tissue elements and, in essence, is subject to a high degree of motion artifact. Any connection, whether wired or wireless, between the recording electrodes and the receiver on a prosthesis will be subject to unpredictable motion and/or strain in an actively moving subject.
Therefore, it is a primary object and feature of the present invention to provide osseointegrated neural interface for interconnecting a prosthetic to a peripheral nerve.
It is a further object and feature of the present invention to provide osseointegrated neural interface for interconnecting a prosthetic to a peripheral nerve wherein the peripheral nerves (e.g. sciatic or median) is redirected into an intramedullary canal of long-bone (e.g. humerus, femur) after amputation.
It is a further object and feature of the present invention to provide osseointegrated neural interface for interconnecting a prosthetic to a peripheral nerve wherein a hollow core rod defines an implant platform which includes various perforations and circuitry necessary to transmit recorded signals from electrodes operatively connected to the peripheral nerve to the prosthetic or provide electrical stimulation to the peripheral nerve.
It is a further object and feature of the present invention to provide osseointegrated neural interface for interconnecting a prosthetic to a peripheral nerve which includes electrode arrays connected to circuitry within hollow core implant platform.
It is a further object and feature of the present invention to provide an osseointegrated neural interface for interconnecting a prosthetic to a peripheral nerve including an implant platform positionable in an intramedullary canal of a long-bone (e.g., humerus, femur) and allowing for passage of a nerve sprout through fenestrations in the implant platform.
It is a further object and feature of the present invention to provide an osseointegrated neural interface for interconnecting a prosthetic to a peripheral nerve including thin flexible electrode arrays (cuff and/or sieve) that are integrated within an implant platform for interfacing a peripheral nerve of interest using microsurgical techniques.
It is a still further object and feature of the present invention to provide an osseointegrated neural interface for interconnecting a prosthetic to a peripheral nerve including an anchor for interconnecting a nerve stump to a long-bone that is stable and immobile.
In accordance with the present invention, an osseointegrated neural interface (ONI) for control of a prosthetic is provided. The osseointegrated neural interface includes an elongated, hollow rod having a first end receiveable in an intramedullary cavity of a bone, a second end operatively connected to the prosthetic and an inner surface defining a cavity. An electrode is receiveable on a terminal end of a peripheral nerve and positionable within the cavity of the rod. The electrode senses the neural signals generated by the peripheral nerve.
An anchor is extendable about peripheral nerve and is receiveable in an opening in the bone. The anchor secures the peripheral nerve to the bone. The electrode includes a plurality of openings therethrough. The plurality of openings are adapted for allowing the passage of nerve sprouts from the peripheral nerve therethrough. The rod includes a plurality of fenestrations extending therethrough. The plurality of fenestrations are adapted for allowing the passage of nerve sprouts from the peripheral nerve therethrough. The electrode may include a base and a plurality of spikes projecting therefrom. The spikes sense the neural signals generated by the peripheral nerve and/or also stimulate the peripheral nerve.
The electrode is operatively connected to a recording unit and/or a stimulation unit. The recording unit recording the neural signals from the peripheral nerve sensed by the electrode. The recording unit may be receivable within the cavity of the rod. A controller is operatively connected to the recording unit. The controller controls operation of the prosthetic in response to the neural signals recorded by the recording unit. In addition, it is contemplated for the controller to send electrical stimulation pulses to the peripheral nerve based on information received from various additional sensors provided in the prosthetic (e.g., pressure, temperature, position, etc). These sensors are meant to recapitulate the natural sensations perceived by the normal limb.
In accordance with a further aspect of the present invention, a method is provided of controlling a prosthetic. The method includes the step of positioning a first end of an elongated, hollow rod within an intramedullary cavity of a bone. The rod has an inner surface defining a cavity. A second end of the rod is interconnected to the prosthetic. A terminal end of a peripheral nerve is positioned within the cavity of the rod. The neural signals generated by the peripheral nerve are monitored and movement of the prosthetic is controlled in response to the neural signals monitored.
The peripheral nerve may be anchored to the bone and an electrode may be positioned on a terminal end of the peripheral nerve. The electrode senses the neural signals generated by the peripheral nerve. The electrode is configured to allow nerve sprouts extending from the peripheral nerve to pass therethrough and the rod is configured to allow the nerve sprouts extending from the peripheral nerve to pass therethrough. The rod includes a plurality of fenestrations extending therethrough. The plurality of fenestrations is adapted for allowing the passage of nerve sprouts from the peripheral nerve therethrough. The fenestrations may also define locations for annular electrodes. The annular electrodes may surround the fenestrations so as to make intimate contact with nerve processes that sprout through the fenstrations.
Movement of the prosthetic is controlled in response to the neural signals monitored by positioning an electrode about the peripheral nerve. The neural signals from the peripheral nerve sensed by the electrode are recorded. Operation of the prosthetic is controlled in response to the neural signals recorded. The recording unit is positioned in the cavity in the rod and operatively connected to the electrode. A controller is positioned in the prosthetic. The controller is configured to control operation of the prosthetic in response to the neural signals recorded by the recording unit and/or to control operation through receiving sensed inputs from various sensors within the prosthetic and stimulate the peripheral nerve accordingly. The controller is operatively connected to the recording unit to receive the neural signals recorded by the recording unit and/or to a stimulating unit to stimulate nerves to provide artificial sensation of the prosthetic.